Haemoglobin Flashcards
What type of molecule is haemoglobin?
A globular protein with a quaternary structure.
What prosthetic group is in haemoglobin?
haem
What does loading/association mean?
When haemoglobin binds to oxygen.
What does unloading/dissociating mean?
When haemoglobin releases the oxygen.
What does affinity mean?
-The tendency of oxygen to bind to haemoglobin.
What does saturation mean?
What is dexoy- and oxyhaemoglobin.
How much oxygen is bound to the haemoglobin, if bound it is oxyhaemoglobin if not bound it is deoxyhaemoglobin.
How does affinity effect how haemoglobin binds to oxygen?
-Ig high oxygen will easily bind but be more difficult to release.
-If low it is difficult to bond and easier to release.
How many molecules of oxygen can bind to 1 molecule of haemoglobin at a time and why?
4 molecules because there are 4 haem groups.
What is the process of oxygen binding to haemoglobin (cooperative binding)?
-When O2 binds to haemoglobin (very hard for the first one) it makes it easier for the 2nd and 3rd as it undergoes a conformational change.
-The 4th O2 has a harder time binding as the molecule is now saturated.
What happens to haemoglobin binding in respiring cells?
There is a low partial pressure so little oxygen binds and oxygen is unloaded as there is a low affinity for oxygen.
What happens to haemoglobin binding in the lungs?
At a high partial pressure lots of oxygen binds and more oxygen is loaded as there is a high affinity for oxygen.
Which factors can effect the curve in a haemoglobin graph and how?
-Location- if there is a high altertiude there is a lower partial pressure so the curve moves to the left.
-Activity-More CO2 is produced so curve moves to right.
-Size- smaller mammals have a higher metabolism so curve moves to right.
How does foetal haemoglobin effect the curve?
-moves to the left as the foetus has higher affinity to oxygen then maternal HB.
-So foetus can load O2 in an area where the mother will unload O2.
